// Copyright (c) 2015-2016 The Bitcoin Core developers
// Distributed under the MIT software license, see the accompanying
// file COPYING or http://www.opensource.org/licenses/mit-license.php.

#include <qt/platformstyle.h>

#include <qt/guiconstants.h>

#include <QApplication>
#include <QColor>
#include <QIcon>
#include <QImage>
#include <QPalette>
#include <QPixmap>

static const struct {
    const char *platformId;
    /** Show images on push buttons */
    const bool imagesOnButtons;
    /** Colorize single-color icons */
    const bool colorizeIcons;
    /** Extra padding/spacing in transactionview */
    const bool useExtraSpacing;
} platform_styles[] = {{"macosx", false, false, true},
                       {"windows", true, false, false},
                       /* Other: linux, unix, ... */
                       {"other", true, true, false}};
static const unsigned platform_styles_count =
    sizeof(platform_styles) / sizeof(*platform_styles);

namespace {

/* Local functions for colorizing single-color images */
void MakeSingleColorImage(QImage &img, const QColor &colorbase) {
    img = img.convertToFormat(QImage::Format_ARGB32);
    for (int x = img.width(); x--;) {
        for (int y = img.height(); y--;) {
            const QRgb rgb = img.pixel(x, y);
            img.setPixel(x, y,
                         qRgba(colorbase.red(), colorbase.green(),
                               colorbase.blue(), qAlpha(rgb)));
        }
    }
}

QIcon ColorizeIcon(const QIcon &ico, const QColor &colorbase) {
    QIcon new_ico;
    for (const QSize &sz : ico.availableSizes()) {
        QImage img(ico.pixmap(sz).toImage());
        MakeSingleColorImage(img, colorbase);
        new_ico.addPixmap(QPixmap::fromImage(img));
    }
    return new_ico;
}

QImage ColorizeImage(const QString &filename, const QColor &colorbase) {
    QImage img(filename);
    MakeSingleColorImage(img, colorbase);
    return img;
}

QIcon ColorizeIcon(const QString &filename, const QColor &colorbase) {
    return QIcon(QPixmap::fromImage(ColorizeImage(filename, colorbase)));
}
} // namespace

PlatformStyle::PlatformStyle(const QString &_name, bool _imagesOnButtons,
                             bool _colorizeIcons, bool _useExtraSpacing)
    : name(_name), imagesOnButtons(_imagesOnButtons),
      colorizeIcons(_colorizeIcons), useExtraSpacing(_useExtraSpacing),
      singleColor(0, 0, 0), textColor(0, 0, 0) {
    // Determine icon highlighting color
    if (colorizeIcons) {
        const QColor colorHighlightBg(
            QApplication::palette().color(QPalette::Highlight));
        const QColor colorHighlightFg(
            QApplication::palette().color(QPalette::HighlightedText));
        const QColor colorText(
            QApplication::palette().color(QPalette::WindowText));
        const int colorTextLightness = colorText.lightness();
        QColor colorbase;
        if (abs(colorHighlightBg.lightness() - colorTextLightness) <
            abs(colorHighlightFg.lightness() - colorTextLightness)) {
            colorbase = colorHighlightBg;
        } else {
            colorbase = colorHighlightFg;
        }
        singleColor = colorbase;
    }
    // Determine text color
    textColor = QColor(QApplication::palette().color(QPalette::WindowText));
}

QImage PlatformStyle::SingleColorImage(const QString &filename) const {
    if (!colorizeIcons) {
        return QImage(filename);
    }
    return ColorizeImage(filename, SingleColor());
}

QIcon PlatformStyle::SingleColorIcon(const QString &filename) const {
    if (!colorizeIcons) {
        return QIcon(filename);
    }
    return ColorizeIcon(filename, SingleColor());
}

QIcon PlatformStyle::SingleColorIcon(const QIcon &icon) const {
    if (!colorizeIcons) {
        return icon;
    }
    return ColorizeIcon(icon, SingleColor());
}

QIcon PlatformStyle::TextColorIcon(const QString &filename) const {
    return ColorizeIcon(filename, TextColor());
}

QIcon PlatformStyle::TextColorIcon(const QIcon &icon) const {
    return ColorizeIcon(icon, TextColor());
}

const PlatformStyle *PlatformStyle::instantiate(const QString &platformId) {
    for (unsigned x = 0; x < platform_styles_count; ++x) {
        if (platformId == platform_styles[x].platformId) {
            return new PlatformStyle(platform_styles[x].platformId,
                                     platform_styles[x].imagesOnButtons,
                                     platform_styles[x].colorizeIcons,
                                     platform_styles[x].useExtraSpacing);
        }
    }
    return nullptr;
}
